Assessment of risk factors for cerebral oxygen desaturation during neonatal and infant general anesthesia: an observational, prospective study

Influence of blood loss on cerebral oxygen saturation in paediatric patients undergoing surgery for scoliosis correction: A retrospective observational study

AIM

Surgery for congenital scoliosis correction in children is often associated with considerable blood loss. Decrease in regional oxygen saturation (rScO2) can reflect insufficient cerebral perfusion and predict neurological complications. This retrospective observational study explored the relationship between blood loss during this surgery and a decrease in rScO2 in children.

METHODS

The following clinical data of children aged 3-14 years who underwent elective posterior scoliosis correction between March 2019 and July 2021 were collected: age, sex, height, weight, baseline rScO2, basal mean invasive arterial pressure (MAP), preoperative Cobb angle, number of surgical segments, preoperative and postoperative haemoglobin level, percentage of lowest rScO2 below the baseline value that lasted 3 min or more during the operation (decline of rScO2 from baseline, D-rScO2%), intraoperative average invasive MAP, end-tidal carbon dioxide pressure, fluid infusion rate of crystalloids and colloids, operation time, and percentage of total blood loss/patient's blood volume (TBL/PBV).

RESULTS

A total of 105 children were included in the study. Massive haemorrhage (TBL/PBV ≥50%) was reported in 53.3% of patients, who had significantly higher D-rScO2 (%) (t = -5.264, P < 0.001) than those who had non-massive haemorrhage (TBL/PBV <50%). Multiple regression analysis revealed that TBL/PBV (β = 0.04, 95% CI: 0.018-0.062, P < 0.05) was significantly associated with D-rScO2%.

CONCLUSIONS

Intraoperative massive blood loss in children significantly increased D-rScO2%. Monitoring should be improved, and timely blood supplementation should be performed to ensure maintenance of the blood and oxygen supply to vital organs, improve the safety of anaesthesia, and avoid neurological complications.

Development of a nomogram to predict negative postoperative behavioral changes based on a prospective cohort

BACKGROUND

It is believed that negative postoperative behavioral changes (NPOBC) is associated with negative perioperative outcomes in children. The importance of development of a predictive model of NPOBC was noted. This study aims to identify potential risk factors develop a nomogram to predict NPOBC on postoperative day 3 based on a prospective cohort.

METHODS

A prospective observational study was conducted on children(American Society of Anesthesiologists I ~ III) aged 2 ~ 12 years who underwent selective surgery under general anesthesia between September 2022 and February 2023. The patient's clinical data were analyzed. The method of measuring NPOBC is with the The Posthospital Behaviour Questionnaire (PHBQ), and all of children remained hospitalized at the time of assessment. The enrolled patients were categorized into the NPOBC group and the non-NPOBC group according to if children developed NPOBC on postoperative day 3. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors and develop the nomogram to predict NPOBC. Internal validation was performed using the parametric bootstrapping method.

RESULTS

One hundred ninety-two patients were enrolled in the study, 44.8% (86/192 patients) of children developed NPOBC on postoperative day 3. Univariate and multivariate logistic regression analysis demonstrated that the Pediatric Anesthesia Behavior (PAB) score (OR: 1.23, 95%CI: 1.14-1.33), cerebral desaturation (OR: 1.16, 95%CI: 1.02-1.32), and postoperative pain score (OR: 1.07, 95%CI: 1.02-1.13) were independent predictors for NPOBC on postoperative day 3 (P < 0.05). They were used to develop the prediction model. The calibration curve demonstrated satisfied discrimination and calibration of the prediction model. The model presented with good discriminative ability (area under the receiver operating characteristic curve: 0.762 [95%CI: 0.691-0.833]). The decision curve analysis also revealed the great clinical utility of the nomogram.

CONCLUSION

Based on our prospective observational study, pre-anesthesia patients with higher PAB scores, presence of cerebral desaturation, and higher postoperative pain score were more likely to develop NPOBC on postoperative day 3. We established and validated a nomogram for predicting NPOBC, which could help assess patients individually, identify high-risk groups of NPOBC and improve patient prognosis.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR-2,200,059,776. Registered 11 May 2022.

Reduced regional cerebral oxygen saturation increases risk for emergence delirium in pediatric patients

Objectives

To assess whether decreased regional cerebral oxygen saturation (rScO₂) is associated with the emergence delirium (ED) following general anesthesia in the pediatric population.

Methods

A retrospective observational cohort study was conducted on 113 children (ASA I-III) aged 2-14 years who underwent selective surgery under general anesthesia between 2022-01 and 2022-04. Intraoperatively, the rScO₂ was monitored using a cerebral oximeter. The Pediatric Anesthesia Emergence Delirium (PAED) score was used to evaluate the patients for ED.

Results

The incidence of ED was 31%. Low rScO₂ was reported in 41.6% of patients, who had a higher incidence of ED (P < 0.001) than those who did not experience desaturation. Logistic regression analysis revealed that decreased rScO₂ was significantly associated with incident ED events [odds ratio (OR), 10.77; 95% confidence interval, 3.31-35.05]. Children under 3 years of age had a higher incidence of ED after rScO₂ desaturation during anesthesia compared to older children (OR, 14.17 vs. 4.64).

Conclusion

Intraoperative rScO₂ desaturation significantly increased the incidence of ED following general anesthesia. Monitoring should be enhanced to improve the oxygen balance in vital organs to improve the quality and safety of anesthesia.

Comparison of cerebral oxygen desaturation events between children under general anesthesia and chloral hydrate sedation - a randomized controlled trial

BACKGROUND

During pediatric general anesthesia (GA) and sedation, clinicians aim to maintain physiological parameters within normal ranges. Accordingly, regional cerebral oxygen saturation (rScO2) should not drop below preintervention baselines. Our study compared rScO2 desaturation events in children undergoing GA or chloral hydrate sedation (CHS).

METHODS

Ninety-two children undergoing long auditory assessments were randomly assigned to two study arms: CHS (n = 40) and GA (n = 52). Data of 81 children (mean age 13.8 months, range 1-36 months) were analyzed. In the GA group, we followed a predefined 10 N concept (no fear, no pain, normovolemia, normotension, normocardia, normoxemia, normocapnia, normonatremia, normoglycemia, and normothermia). In this group, ENT surgeons performed minor interventions in 29 patients based on intraprocedural microscopic ear examinations. In the CHS group, recommendations for monitoring and treatment of children undergoing moderate sedation were met. Furthermore, children received a double-barreled nasal oxygen cannula to measure end-tidal carbon dioxide (etCO2) and allow oxygen administration. Chloral hydrate was administered in the parent's presence. Children had no intravenous access which is an advantage of sedation techniques. In both groups, recommendations for fasting were followed and an experienced anesthesiologist was present during the entire procedure. Adverse event (AE) was a decline in cerebral oxygenation to below 50% or below 20% from the baseline for ≥1 min. The primary endpoint was the number of children with AE across the study arms. Secondary variables were: fraction of inspired oxygen (FIO2), oxygen saturation (SpO2), etCO2, systolic and mean blood pressure (BP), and heart rate (HR); these variables were analyzed for their association with drop in rScO2 to below baseline (%drop_rScO2).

RESULTS

The incidence of AE across groups was not different. The analysis of secondary endpoints showed evidence that %drop_rScO2 is more dependent on HR and FIO2 than on BP and etCO2.

CONCLUSIONS

This study highlights the strong association between HR and rScO2 in children aged < 3 years, whereas previous studies had primarily discussed the role of BP and etCO2. Prompt HR correction may result in shorter periods of cerebral desaturation.

TRIAL REGISTRATION

The study was retrospectively registered with the German Clinical Trials Registry (DRKS00024362, 04/02/2021).

Use of combined cerebral and somatic renal near infrared spectroscopy during noncardiac surgery in children: a proposed algorithm

Cerebral near infrared spectroscopy (NIRS) monitoring has been extensively applied in neonatology and in cardiac surgery, becoming a standard in many pediatric cardiac centers. However, compensatory physiological mechanisms favor cerebral perfusion to the detriment of peripheral tissue oxygenation. Therefore, simultaneous measurement of cerebral and somatic oxygen saturation has been advocated to ease the differential diagnosis between central and peripheral sources of hypoperfusion, which may go undetected by standard monitoring and not mirrored by cerebral NIRS alone. A clinical algorithm already exists in cardiac surgery, aimed to correct intraoperative cerebral oxygen desaturations. A similar algorithm still lacks in noncardiac pediatric surgery. The goal of this paper is to propose a clinical algorithm for the combined use of cerebral and somatic NIRS monitoring during anesthesia in the pediatric population undergoing noncardiac surgery. A panel of experienced pediatric anesthetists developed the algorithm that is based on the clinical experience and intraoperative observations. It aims to lessen the current variability in interpreting NIRS measurement. Multisite NIRS monitoring was achieved applying one pediatric sensor to the forehead for cerebral tissue perfusion reading and a second one to the decumbent lumbar region for recording somatic renal tissue perfusion. The algorithm describes a sequence of acts aimed to identify the putative cause of intraoperative organ tissue desaturation and suggests clinical interventions expected to restore adequate tissue perfusion. It is composed of two arms: the main arm includes patients with an observed decrease in cerebral perfusion (CrO2), the second one includes those with a stable CrSO2 with declining RrSO2. Described also are five clinical cases of infants and neonates in whom pathological alterations of organ perfusion were detected using intraoperative multisite NIRS monitoring, portrayed in the accompanying figures (Annex).

Intraoperative cerebral oxygen saturation and neurological outcomes following surgical management of necrotizing enterocolitis: Predictive factors of neurological complications following neonatal necrotizing enterocolitis: Predictive factors of neurological complications following neonatal necrotizing enterocolitis

BACKGROUND

The goal of the present study was to investigate intraoperative factors associated with major neurological complications at 1 year following surgery for necrotizing enterocolitis.

MATERIAL AND METHODS

The study consisted of a retrospective review of medical charts of patients operated for over one calendar year in one institution. Data collected included demographic data, cardiac resuscitation at birth, Bell classification, antibiotics usage, time of day of surgery, surgical technique, surgical duration, type of ventilation, intraoperative vasoactive agents, and albumin use, nadir cerebral saturation, the decrease in cerebral saturation from baseline, the time period when cerebral saturation was at least 20% below baseline, and the mean arterial pressure at nadir cerebral saturation. Reported follow-up complications were assessed during formal neonatologist consultation and additional imaging exploration as needed. Analyses included descriptive statistics, and univariable and multivariable statistics.

RESULTS

The study included 32 patients with no prior clinical neurological complications, of which 25 had normal cerebral imaging. Severe neurological complications occurred in nine patients at 1 year: Intraventricular hemorrhage (N = 2) and Periventricular leukomalacia (N = 7). However, preoperative cerebral imaging was lacking in seven patients. Consequently, the observed neurological complications at 1 year might be present before the surgery. Multivariable analysis found the decrease in cerebral saturation ≥36% from baseline as the only factor associated with the occurrence of those complications.

CONCLUSION

Intraoperative decrease of cerebral oxygen saturation below ≥36% from baseline is associated with severe neurological complications in neonates undergoing surgery for necrotizing enterocolitis.

Effect of hemoglobin content on cerebral oxygen saturation during surgery for scoliosis in pediatric patients

BACKGROUND

Although regional cerebral oxygen saturation (rScO₂) monitoring has been widely used in clinical practice, the relationship between hemoglobin (dHB) content and rScO₂ is incompletely understood. The aim of this study was to analyze the effect of hemoglobin content on rScO₂ in pediatric patients undergoing general anesthesia for correction of scoliosis.

METHODS

Ninety-two pediatric patients aged 3 to 14 years undergoing scoliosis correction surgery were enrolled. Continuous monitoring of bilateral regional cerebral oxygen saturation by near-infrared spectroscopy (NIRS, CASMED, USA) was performed after entering the operation room. rScO₂ was recorded when the patients entered the operating room (T₀, baseline), after anesthesia induced intubation (T₁), and after radial artery puncture (T₂). The lowest value of rScO₂ during surgery was also recorded. The arterial blood pressure (ABP), heart rate (HR), pulse oxygen saturation (SpO₂), end tidal carbon dioxide partial pressure (PetCO₂) were continuously recorded. Patients were classified as low rScO₂ or high rScO₂ group according to whether the lowest intraoperative rScO₂ was 15% lower than the baseline value. An analysis and comparison of differences in hemoglobin content in these two groups was carried out.

RESULTS

The preoperative hemoglobin-postoperative hemoglobin of patients in the high rScO₂ group was significantly lower than that in the low rScO₂ group (t = - 7.86, p < 0.01), the amount of bleeding during the operation was also less than that in the low rScO₂ group (t = - 6.05, p < 0.01), and the systolic pressure of patients was higher than that in the low rScO₂ group (t = 4.27, p < 0.01).

CONCLUSIONS

The decrease in hemoglobin level which occurs during surgery leads to a decrease in cerebral oxygen saturation. In order to ensure patient safety during surgery, it is necessary to carry out volume management and appropriate transfusion and fluid replacement in a timely manner.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1800016359 . Registered 28 May 2018.

The Behavioral Problems in 2.5-5 Years Old Children Linked with Former Neonatal/Infantile Surgical Parameters

Studies report the link between exposure to major neonatal surgery and the risk of later neurodevelopmental disorders. The aim of this study was to find out the behavioral problem scores of 2.5–5 years old children who had undergone median/major non-cardiac surgery before the age of 90 days, and to relate these to intraoperative cerebral tissue oxygenation values (rSO₂), perioperative duration of mechanical ventilation (DMV) and doses of sedative/analgesic agents. Internalizing (IP) and externalizing problems (EP) of 34 children were assessed using the CBCL for ages 1½–5. Median (range) IP and EP scores were 8.5 (2–42) and 15.5 (5–33), respectively and did not correlate with intraoperative rSO₂. DMV correlated and was predictive for EP (β (95% CI) 0.095 (0.043; 0.148)). An aggregate variable “opioid dose per days of ventilation” was predictive for EP after adjusting for patients’ gestational age and age at the day of psychological assessment, after further adjustment for age at the day of surgery and for cumulative dose of benzodiazepines (β (95% CI 0.009 (0.003; 0.014) and 0.008 (0.002; 0.014), respectively). Neonatal/infantile intraoperative cerebral oxygenation was not associated with later behavioral problems. The risk factors for externalizing problems appeared to be similar to the risk factors in preterm infant population.

Towards integrative neuromonitoring of the surgical newborn: A systematic review

BACKGROUND

The altered neurodevelopment of children operated on during the neonatal period might be due to peri-operative changes in the homeostasis of brain perfusion. Monitoring of vital signs is a standard of care, but it does not usually include monitoring of the brain.

OBJECTIVES

To evaluate methods of monitoring the brain that might be of value. We also wanted to clarify if there are specific risk factors that result in peri-operative changes and how this might be evaluated.

DESIGN

Systematic review.

DATA SOURCES

A structured literature search was performed in MEDLINE in Ovid, Embase, Cochrane CENTRAL, Web of Science and Google Scholar.

ELIGIBILITY CRITERIA

Studies in neonates who received peri-operative neuromonitoring were eligible for inclusion; studies on neurosurgical procedures or cardiac surgery with cardiopulmonary bypass and/or deep hypothermia cardiac arrest were excluded.

RESULTS

Nineteen of the 24 included studies, totalling 374 infants, reported the use of near-infrared spectroscopy. Baseline values of cerebral oxygenation greatly varied (mean 53 to 91%) and consequently, no coherent results were found. Two studies found a correlation between cerebral oxygenation and mean arterial blood pressure. Five studies, with in total 388 infants, used (amplitude-integrated) electro-encephalography to study peri-operative brain activity. Overall, the brain activity decreased during anaesthesia and epileptic activity was more frequent in the peri-operative phase. The association between intra-operative cerebral saturation or activity and neuro-imaging abnormalities and/or neurodevelopmental outcome was investigated in six studies, but no association was found.

CONCLUSION

Neuromonitoring with the techniques currently used will neither help our understanding of the altered neonatal pathophysiology, nor enable early detection of deviation from the norm. The modalities lack specificity and are not related to clinical (long-term) outcome or prognosis. Accordingly, we were unable to draw up a monitoring guideline.

Near-Infrared Spectroscopy Monitoring in Pediatric Anesthesiology: A Pro-Con Discussion

Near-infrared spectroscopy (NIRS) has been increasingly used as a non-invasive measurement of cerebral tissue oxygen saturation. The aim of this short review is to discuss the benefits and drawbacks of its use in the pediatric anesthesia population. In the context of cardiac surgery, lower intraoperative NIRS values have shown a modest association with neurodevelopmental outcomes while lower neonatal intensive care unit NIRS values have been correlated with reduced neurodevelopment in children. However, it is still unclear if management aimed at increasing cerebral tissue oxygenation would have any benefit on these outcomes. Without prospective research looking into the effects of intervention given proper thresholds, the true benefit of NIRS use is still up for debate. Even with current research gaps, its use in the clinical setting continues.

Predictors of hypoxemia after general anesthesia in the early postoperative period in a hospital in Ethiopia: an observational study

BACKGROUND

Early postoperative hypoxemia is a common problem after general anesthesia. The identification of factors associated with an increased occurrence of it might help healthcare professionals to hypoxemia risk patients, therefore this study aims to assess the incidence and factors associated with early postoperative hypoxemia among surgical procedures.

METHODS

A prospective cohort study design was conducted from February 1, 2020 to June 30, 2020, on a total of 424 patients who underwent surgery under general anesthesia in Debre Tabor Comprehensive Specialized Hospital. The data was collected using a structured checklist. Bivariable and multivariable logistic regressions were used to check the association.

RESULTS

The incidence of early postoperative hypoxemia was 45.8%. Patients having a BMI of 25-29.9 kg/m2 and BMI of 30-39.9 kg/m2, patients having a chronic disease, current smokers, SPO2 reading before induction of less than 95%, emergency surgery, and the absence of oxygen therapy during the period of transfer and/or in the post anesthesia care unit were significantly associated with an increased risk of hypoxemia in the early postoperative period.

CONCLUSIONS

The incidence of early postoperative hypoxemia was high in Debre Tabor Comprehensive Specialized Hospital. Obese patients, patients having a chronic disease, current smokers, and lower oxygen saturations before induction, emergency surgery, and the absence of oxygen therapy were the main predictors of an increased occurrence of early postoperative hypoxemia.

Effect of Permissive Mild Hypercapnia on Cerebral Vasoreactivity in Infants: A Randomized Controlled Crossover Trial

BACKGROUND

Mechanical ventilation interferes with cerebral perfusion via changes in intrathoracic pressure and/or as a consequence of alterations in CO2. Cerebral vascular vasoreactivity is dependent on CO2, and hypocapnia can potentially lead to vasoconstriction and subsequent decrease in cerebral blood flow. Thus, we aimed at characterizing whether protective ventilation with mild permissive hypercapnia improves cerebral perfusion in infants.

METHODS

Following ethical approval and parental consent, 19 infants were included in this crossover study and randomly assigned to 2 groups for which the initial ventilation parameters were set to achieve an end-tidal carbon dioxide (Etco2) of 6.5 kPa (group H: mild hypercapnia, n = 8) or 5.5 kPa (group N: normocapnia, n = 11). The threshold was then reversed before going back to the initial set value of normo- or hypercapnia. At each step, hemodynamic, respiratory, and near-infrared spectroscopy (NIRS)-derived parameters, including tissue oxygenation index (TOI) and tissue hemoglobin index (THI), concentration of deoxygenated hemoglobin (HHb) and oxygenated hemoglobin (O2Hb), were collected. Concomitantly, sevoflurane maintenance concentration, ventilatory (driving pressure) and hemodynamic parameters, as mean arterial pressure (MAP), were recorded.

RESULTS

Targeting an Etco2 of 5.5 kPa resulted in significantly higher mean driving pressure than an Etco2 of 6.5 kPa (P < .01) with no difference between the groups in end-tidal sevoflurane, MAP, and heart rate. A large scatter was observed in NIRS-derived parameters, with no evidence for difference in Etco2 changes between or within groups. A mild decrease with time was observed in THI and MAP in infants randomly assigned to group N (P < .036 and P < .017, respectively). When pooling all groups together, a significant correlation was found between the changes in MAP and TOI (r = 0.481, P < .001).

CONCLUSIONS

Allowing permissive mild hypercapnia during mechanical ventilation of infants led to lower driving pressure and comparable hemodynamic, respiratory, and cerebral oxygenation parameters than during normocapnia. Whereas a large scatter in NIRS-derived parameters was observed at all levels of Etco2, the correlation between TOI and MAP suggests that arterial pressure is an important component of cerebral oxygenation at mild hypercapnia.

Potential Relationship between Cerebral Fractional Tissue Oxygen Extraction (FTOE) and the Use of Sedative Agents during the Perioperative Period in Neonates and Infants

Fractional tissue oxygen extraction (FTOE) by means of cerebral near-infrared spectroscopy (NIRS) provides information about oxygen uptake in the brain. Experimental animal data suggest that sedative agents decrease cerebral oxygen demand. The aim of the present study was to investigate the association between the cerebral FTOE and the use of pre and intraoperative sedative agents in infants aged 1-90 days. Cerebral NIRS was continuously applied during open major non-cardiac surgery in 46 infants. The main outcomes were the mean intraoperative FTOE and the percentage (%) of time of intraoperative hyperoxia_FTOE relative to the total duration of anesthesia. Hyperoxia_FTOE was defined as FTOE ≤ 0.1. Cumulative doses of sedative agents (benzodiazepines and morphine), given up to 24 h preoperatively, correlated with the mean intraoperative FTOE (Spearman's rho = -0.298, p = 0.0440) and were predictive for the % of time of intraoperative hyperoxia_FTOE (β (95% CI) 47.12 (7.32; 86.92)) when adjusted for the patients' age, type of surgery, preoperative hemoglobin, intraoperative sevoflurane and fentanyl dose, mean intraoperative arterial blood pressure, and end-tidal CO₂ by multivariate 0.75 quantile regression. There was no association with 0.5 quantile regression. We observed the suggestive positive association of decreased fractional cerebral tissue oxygen extraction and the use of sedative agents in neonates and infants undergoing surgery.

Cerebral oxygenation during pediatric congenital cardiac surgery and its association with outcome: a retrospective observational study

PURPOSE

Non-invasive cerebral oxygen saturation (ScO2) monitoring is an established tool in the intraoperative phase of pediatric congenital cardiac surgery (CCS). This study investigated the association between ScO2 and postoperative outcome by investigating both baseline ScO2 values and intraoperative desaturations from baseline.

METHODS

All CCS procedures performed in the period 2010-2017 in our institution in which ScO2 was monitored were included in this historical cohort study. Baseline ScO2 was determined after tracheal intubation, before surgical incision. Subgroups were based on cardiac pathology and degree of intracardiac shunting. Poor outcome was defined based on length of stay (LOS) in the intensive care unit (ICU)/hospital, duration of mechanical ventilation (MV), and 30-day mortality. Intraoperatively, ScO2 total time below baseline (TBBL) and ScO2 time-weighted average (TWA) were calculated.

RESULTS

Data from 565 patients were analyzed. Baseline ScO2 was significantly associated with LOS in ICU (odds ratio [OR] per percentage decrease in baseline ScO2, 0.95; 95% confidence interval [CI], 0.93 to 0.97; P < 0.001), with LOS in hospital (OR, 0.93; 95% CI, 0.91 to 0.96; P < 0.001), with MV duration (OR, 0.92; 95% CI, 0.90 to 0.95; P < 0.001) and with 30-day mortality (OR, 0.94; 95% CI, 0.91 to 0.98; P = 0.007). Cerebral oxygen saturation TWA had no associations, while ScO2 TBBL had only a small association with LOS in ICU (OR, 1.02; 95% CI, 1.01 to 1.03; P < 0.001), MV duration (OR,1.02; 95% CI, 1.01 to 1.03; P = 0.002), and LOS in hospital (OR, 1.02; 95% CI, 1.01 to 1.04; P < 0.001).

CONCLUSION

In pediatric patients undergoing cardiac surgery, low baseline ScO2 values measured after tracheal intubation were associated with several adverse postoperative outcomes. In contrast, the severity of actual intraoperative cerebral desaturation was not associated with postoperative outcomes. Baseline ScO2 measured after tracheal intubation may help identify patients at increased perioperative risk.

Near Infrared Spectroscopy in Anemia Detection and Management: A Systematic Review

Red cell transfusions are intended to improve oxygen delivery to tissues. Although studies comparing hemoglobin concentration triggers for transfusion have been done, the hemoglobin threshold for clinical benefit remains uncertain. Direct measurement of tissue oxygenation with non-invasive near infrared spectroscopy has been proposed as a more physiological transfusion trigger, but its clinical role remains unclear. This systematic review examined the role of near infrared spectroscopy for detection of anemia and guiding transfusion decisions. Abstracts were identified up until May 2019 through searches of PubMed, EMBASE and The Web of Science. There were 69 studies meeting the inclusion criteria, most (n = 65) of which were observational studies. Tissue oxygen saturation had been measured in a wide range of clinical settings, with neonatal intensive care (n = 26) and trauma (n = 7) being most common. Correlations with hemoglobin concentration and tissue oxygenation were noted and there were correlations between changes in red cell mass and changes in tissue oxygenation through blood loss or transfusion. The value of tissue oxygenation for predicting transfusion was determined in only four studies, all using muscle oxygen saturation in the adult trauma setting. The overall sensitivity was low at 34% (27%-42%) and while it had better specificity at 78% (74%-82%), differing and retrospective approaches create a high level of uncertainty with respect to these conclusions. There were four prospective randomized studies involving 540 patients, in cardiac and neurological surgery and in neonates that compared near infrared spectroscopy to guide transfusion decisions with standard practice. These showed a reduction in the number of red cells transfused per patient (OR: 0.44 [0.09-0.79]), but not the number of patients who received transfusion (OR: 0.71 [0.46-1.10]), and no change in clinical outcomes. Measuring tissue oxygen saturation has potential to help guide transfusion; however, there is a lack of data upon which to recommend widespread implementation into clinical practice. Standardization of measurements is required and greater research into levels at which tissue oxygenation may lead to adverse clinical outcomes would help in the design of future clinical trials.

Anesthesia management in neonatal congenital bronchobiliary fistula: case report and literature review

Background

There is very little published literature and none that discussed care in a neonate regarding anesthetic risk and management of neonate with congenital bronchobiliary fistula during thoracoscopy and thoracotomy. This article analyzes related risk factors and literature review from perioperative ventilation, circulation and other aspects of management.

Case presentation

A neonate diagnosed as congenital bronchobiliary fistula combined with severe chemical pneumonia, consolidation of the lungs, and infection was facing the risk of anaesthesia under thoracoscopy exploration surgery, who experiened more than 20 days diagnostic period before operation. Many risk factors have led to conversion from minimally invasive surgery to thoracotomy, including persistent hypoxemia, hypercapnia, difficult surgical exposure and extremly difficulty of intraoperative ventilation management. Anesthesia maintenance after conversion to open access remained problematic. Fortunately the patient showed no sign of any adverse CNS effects after 4 months of follow-up.

Conclusions

The most prominent anesthesia challenges are hypoxemia, increased airway resistance, impaired ventilation, and the risk of metabolic acidosis. Close cooperation among the entire neonatal medical team is the key factors in successful management of this rare case.

Beyond Anesthesia Toxicity: Anesthetic Considerations to Lessen the Risk of Neonatal Neurological Injury

Infants who undergo surgical procedures in the first few months of life are at a higher risk of death or subsequent neurodevelopmental abnormalities. Although the pathogenesis of these outcomes is multifactorial, an understanding of the nature and pathogenesis of brain injury in these infants may assist the anesthesiologist in consideration of their day-to-day practice to minimize such risks. This review will summarize the main types of brain injury in preterm and term infants and their key pathways. In addition, the review will address key potential pathogenic pathways that may be modifiable including intraoperative hypotension, hypocapnia, hyperoxia or hypoxia, hypoglycemia, and hyperthermia. Each of these conditions may increase the risk of perioperative neurological injury, but their long-term ramifications are unclear.

A Review of Regional Anesthesia in Infants

Regional anesthesia provides effective anesthesia and pain relief in infants with age-specific data attesting to safety and efficacy. Regional anesthesia decreases exposure to opioids and general anesthetic agents and associated adverse drug effects, suppresses the stress response, and provides better hemodynamic stability compared to general anesthesia. Regional anesthesia can prevent long-term behavioral responses to pain. As a result, the overall number and variety of nerve blocks being used in infants is increasing. While neuraxial blocks are the most common blocks performed in infants, the introduction of ultrasound imaging and a better safety profile has advanced the use of peripheral nerve blocks. Infant-specific pharmacokinetic and pharmacodynamic data of local anesthetic medications are reviewed including risk factors for the accumulation of high serum levels of unbound, pharmacologically active drug. Bupivacaine accumulates with continuous infusion and 2-chloroprocaine can be used as an alternative. Local anesthetic systemic toxicity has the highest incidence in infants less than 6 months of age and is associated with bolus dosing and penile nerve blocks. Local anesthetic toxicity is treated by securing the airway, suppression of seizure activity and implementation of cardiopulmonary resuscitation. Administration of intralipid (intravenous lipid emulsion) is initiated at the first sign of toxicity. A high level of expertise in regional anesthesia is needed when treating infants due to their unique development.

A practical approach to cerebral near-infrared spectroscopy (NIRS) directed hemodynamic management in noncardiac pediatric anesthesia

Safeguarding cerebral function is of major importance during pediatric anesthesia. Premature, ex-premature, and full-term neonates can be vulnerable to physiological changes that occur during anesthesia and surgery. Data from studies performed during pediatric cardiac surgery and in neonatal/pediatric intensive care units have shown the benefits of near-infrared spectroscopy (NIRS) monitoring of regional cerebral oxygenation (c-rSO₂ ). However, NIRS monitoring is seldom used during noncardiac pediatric anesthesia. Despite compelling evidence that blood pressure does not reflect end-organ perfusion, it is still regarded as the most important determinant of cerebral perfusion and the most relevant hemodynamic management target parameter by most (pediatric) anesthetists. The principle of NIRS monitoring is not self-explanatory and sometimes seems even counterintuitive, which may explain why many anesthesiologists are reserved regarding its use. The first part of this paper is dedicated to a clinical introduction to NIRS monitoring. Despite scientific efforts, it has not yet been possible to define individual lower limit c-rSO₂ values and it is unlikely this will succeed in the near future. Nonetheless, published treatment algorithms usually specify c-rSO₂ values which may be associated with cerebral hypoxia. Our treatment guideline for maintaining sufficient cerebral oxygenation differs fundamentally from all previously published approaches. We define a baseline c-rSO₂ value, registered in the awake child prior to anesthesia induction, as the lowest acceptable limit during anesthesia and surgery. The cerebral rSO₂ is the single target parameter, while blood pressure, heart rate, P_a CO₂ , and SaO₂ are major parameters that determine the c-rSO2. Cerebral NIRS monitoring, interpreted together with its continuously available contributing parameters, may help avoid potentially harmful episodes of cerebral desaturation in anesthetized pediatric patients.

Overexpression of phosphoprotein enriched in astrocytes 15 reverses the damage induced by propofol in hippocampal neurons

Propofol is a general anesthetic used in surgical operations. Phosphoprotein enriched in astrocytes 15(PEA15) was initially identified in astrocytes. The present study examined the role of PEA15 in the damage induced by propofol in hippocampal neurons. A model of hippocampal neuron damage was established using 50 µmol/l propofol. Cell viability, proliferation and apoptosis of hippocampal neurons were tested by Cell Counting Kit‑8 and flow cytometry. Western blotting and reverse transcription‑quantitative polymerase chain reaction analysis were performed to measure the expression levels of PEA15, and additional factors involved in apoptosis or in the signaling pathway downstream of PEA15. The present results suggested that propofol significantly decreased PEA15 expression levels in hippocampal neurons. Furthermore, overexpression of PEA15 significantly increased the cell viability and cell proliferation of cells treated with propofol. Additionally, PEA15 overexpression decreased apoptosis, which was promoted by propofol. Treatment with propofol significantly decreased the protein expression levels of pro‑caspase‑3, B‑cell lymphoma-2, phosphorylated extracellular signal‑regulated kinases (ERK)1/2, ribosomal S6 kinase 2 (RSK2) and phosphorylated cAMP responsive element binding protein 1 (CREB1). However, propofol upregulated active caspase‑3 and Bax expression levels. Notably, PEA15 overexpression was able to reverse the effects of propofol. Collectively, overexpression of PEA15 was able to attenuate the neurotoxicity of propofol in rat hippocampal neurons by increasing proliferation and repressing apoptosis via upregulation of the ERK‑CREB‑RSK2 signaling pathway.

Cerebral Oxygen Saturation and Negative Postoperative Behavioral Changes in Pediatric Surgery: A Prospective Observational Study

OBJECTIVE

To evaluate if an intraoperative cerebral regional oxygen saturation (crSO₂) decrease, less pronounced than 20% below baseline (the current threshold believed to be associated with cognitive dysfunction in adults), is associated with negative postoperative behavioral changes (NPOBC) in the pediatric population after noncardiac surgeries.

STUDY DESIGN

A prospective observational study was conducted with 198 children aged 2-12 years old scheduled for noncardiac procedures under general anesthesia. Intraoperatively, crSO₂ was monitored with a cerebral oximeter. On postoperative day 7, the Post-Hospital Behavior Questionnaire was used to diagnose NPOBC.

RESULTS

The incidence of NPOBC was 38.8%. Logistic regression analysis revealed that with every 1% reduction of crSO₂ from the baseline value, the odds of developing NPOBC were 1.199 higher. Likewise, preoperative anxiety (OR 2.832, P = .006), duration of surgery (OR 1.026, P < .0001), and being between the ages of 2 and 3 years (OR 2.604, P = .048) were associated with NPOBC incidence. The multivariable logistic regression model receiver operating characteristic curve showed an area under the curve (95% CI) = 0.820 (0.759-0.881).

CONCLUSIONS

During noncardiac surgeries in the pediatric population, an intraoperative decrease in crSO₂ less pronounced than 20% from the baseline value is associated with negative postoperative behavior changes on postoperative day 7. The long-term implications remain to be determined, but this supports attention to crSO₂ during noncardiac surgeries.

Comparison of effects of low-flow and normal-flow anesthesia on cerebral oxygenation and bispectral index in morbidly obese patients undergoing laparoscopic sleeve gastrectomy: a prospective, randomized clinical trial

Introduction

The effects of low-flow anesthesia on cerebral oxygenation in high-risk, morbidly obese patients are not well known.

Aim

In this prospective randomized study, we compared the effects of low-flow (0.75 l/min) and normal-flow (1.5 l/min) anesthesia on regional cerebral oxygen saturation (rSO₂) and the bispectral index (BIS) in morbidly obese patients undergoing laparoscopic bariatric surgery.

Material and methods

Fifty-two morbidly obese patients undergoing laparoscopic bariatric surgery (sleeve gastrectomy) were enrolled in this study. Patients were randomly allocated to two study groups: low-flow and normal-flow anesthesia groups. Heart rate, mean arterial pressure, peripheral oxygen saturation, end-tidal carbon dioxide, BIS, left and right rSO₂, and duration of anesthesia and surgery were recorded.

Results

The groups were similar with respect to age, gender, height, weight, body mass index, American Society of Anesthesiology physical status, heart rate, duration of anesthesia, and procedure. Mean arterial pressure and end-tidal carbon dioxide, both before and after insufflation of carbon dioxide and after the reverse Trendelenburg position, were significantly higher in the low-flow group. BIS values and left and right rSO₂ during the preoperative and intraoperative periods were similar. Although the difference in right rSO₂ between the two groups after awakening from anesthesia was statistically significant, the results of both groups remained within the normal range and were not clinically meaningful.

Conclusions

Low-flow anesthesia is safe regarding hemodynamic and respiratory characteristics, depth of anesthesia, and regional cerebral oxygen saturation in morbidly obese patients undergoing laparoscopic bariatric surgery.